A while ago, I stumbled upon Julian Crandall Hollick’s journey from the Himalayas to the Bay of Bengal along the river Ganga.
The 6 part audio series discusses various aspects from the nature, to human soiling to the Farakka dam’s drastic impact on the river’s course. Look for all the details at http://www.ibaradio.org/India/ganga/index.htm
I remember my visit to Haridwar 5 years ago and my own observation of how the river gets soiled day in and day out in the name of religion. I also remember my own observation of how the river Bagmati at Pashupatinath temple in Kathmandu. I did not have the guts to place my hand in that water!